Electric heating unit and connector assembly therefor



July 27, 1965 c. w. GILLESPIE ETAL 3, ,6 7

ELECTRIC HEATING UNIT AND CONNECTOR ASSEMBLY THEREFOR Filed April 12, 1961 Fig. 8

INVENTORS Charles W. Gillespie y Ronald L. Leonard orney 2,835,780, issued May 20, 1958.

United States Patent 3,197,o17 ELECTTEHC HEATHNG Ul ll'll AND CGNNECTUR ASSEMBLY THEREFGR Uharies W. Giilespie, Vandalia, and Ronald L. Leonard,

Dayton, Ghio, assignors to General Motors Corporation, Detroit, Mich a corporation of Delaware Filed Apr. 12, 1961, Ser. No. 102,499 1 Claim. (Cl. 219-541) This invention relates to a domestic appliance and more particularly to an improved electrical connector assembly for connecting the top surface heating unit of an electric range with a power supply. In the prior art heating units to which this invention applies, the coiled tubular sheath is formed with a relatively straight terminal portion which extends below the top surface of the electric range for connection with a source of power. To this terminal portion may be connected a terminal block for housing the electrical spade connectors which are selectively electrically engaged through a mating connector block in electrical supply relationship with the power source. The prior art arrangement is shown more particularly in the patent to Bremer In this earlier version, a plurality of subsequent assembly operations are required to attach the various electrical supply components to the tubular sheath. This is not only time consuming and costly, but requires additional components which are eliminated by the teachings of this invention.

Accordingly, it is an object of this invention to provide a terminal block as an integral part of the heating unit.

A more particular object of this invention is the provision of a terminal block which is retained in sealed relationship on the tubular heating unit by the terminal connector tabs.

A general object of this invention is the provision of a terminal block which serves as a process fitting for the assembly of a heating unit.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein preferred embodiments of the present invention are clearly shown.

In the drawings:

FIGURE 1 is a fragmentary top elevational View of an eiectric range provided with a top surface cooking or heating unit suitable for use with this invention;

FIGURE 2 is a fragmentary side elevational view of the heating unit, partly in section;

FIGURE 3 is a partly exploded side sectional view of this invention;

FlGURE 4 is an elevational view taken along line 4-4 in FIGURE 3;

FIGURE 5 is a side sectional view of the terminal block of this invention;

FIGURE 6 is an elevational View taken along line 66 in FIGURE 5;

FIGURE 7 is an elevational View taken along line '77 in FIGURE 5;

FIGURE 8 is an elevational view of a sealing member used in this invention; and

FIGURE 9 is a top elevational view of a connector tab suitable for use with this invention.

In accordance with this invention and with reference to FIGURE 1, an electric range it? is provided with a range top 12 having a trimmed opening 14 therein for receiving a spirally formed tubular sheath top surface heating or cooking unit 16. A terminal portion 18 of the heating unit is substantially straight and downwardly bent to drop below the top 12 of the range as seen in FIGURE 2. This terminal portion 1:; of the heating unit 15 is 3, l 97,6 l 7 Patented July 27, 1965 adapted for pivotally attaching the unit to the range top as well as for electrically connecting the heating unit to a source of power.

The heating unit 16 may be selectively pivotally attached to the underside of the range top 12 as at 20 by a pivot bracket shown generally at 22. The bracket 22 serves to position the heating unit 16 in either a flat horizontal operating position as shown in FIGURE 2 or in a raised position for cleaning. Further details pertaining to the pivot support bracket 22 may be seen in the patent to Bremer 2,948,801, issued August 9, 1960.

To the straight terminal portion 18 of the heating unit 16 may be attached an insulating terminal block 24 which mates in electrical supply relationship with a plug-in cooking unit connector block or insulator 26. The connector 26 is, in turn, electrically connected to an electrical power supply as evidenced by the power supply leads 2%.

Turning now to FTGURE 3 the construction of the integrally assembled terminal block of this invention will be explained more fully. The straight portion 18 of the heating unit to is formed with a cylindrical end portion 343 defined by an annular groove 32 spaced from the end of the heating unit. The straight portion 18 forms a tubular sheath to which a pair of heating coils or resistance elements 34, 36 extend. To the coiled resistance or heating element 34 is attached a generally straight electrical conductor portion or terminal wire 33 and to the coil 36 a terminal wire 4% The ends of the terminal wires 33 and 49, it will be noted, extend outside the sheath beyond the end of the cylindrical portion 3ft. A ceramic insulator or terminal alignment bushing 42 seats within the cylindrical end portion 3%? against the annular rib 32 and includes a pair of openings which receive the terminals 33 and 4t and serve to center them within the tubular sheath 18 in permanently fixed and spaced relationship thereto. The terminal block 24 is formed with a pocket 5i? which fits over the exposed ends of the terminals 38 and 4t and sandwiches a resilient gasket or sealing member 43 of silastic or other suitable material between the end of the cylindrical portion 3d and the terminal block 24. Lastly, a pair of electrical spades or connector tabs 44, 46 are fastened to the ends of the terminals 38 and 49. More particularly, the connector tab 44 includes a welding boss such as 45 which is fastened as by welding to the end of the terminal wire 38, whereas the connector tab 46 is fastened as by welding to the terminal wire 49. Thus, when the power supply connector block 26 is plugged into the terminal block. 24, the connector tabs 44 and as are engaged to condition the heating unit 16 for selective energization.

With reference to FIGURES 5, 6 and 7, the novel terminal block of this invention is shown to be generally drum-like in shape. At one end is formed a cylindrical pocket or recess St) for receiving the cylindrical end 3% of the tubular sheath. At the opposite end is formed a connector block receiving socket or recess 52. Interconnecting the recesses 59 and 52 are terminal ports 54 and 56 through an interconnecting wall portion of the terminal block 24. At the end of the terminal ports 54 and 56 adjacent the socket 52 are enlarged or flared sections or welding recesses 53 and 69, the purpose of which will be explained hereinafter. The terminal block 24 may be formed of black Bakelite or other suitable insulator material which may be readily molded or formed to the desired configuration.

The following method steps may be used to assemble the foregoing components into a finished spirally formed top surface heating unit. The assembly operation starts by joining each resistance coil to its respective terminal wire. After the coils and terminal wires are fastened together, a ported ceramic insulator 42 is slipped over the ends of the terminal Wires to hold the terminals in properly spaced relationship.

Next, the gask t 43 is slipped over the ends of the terminals 33 and 4tlopenings, such as 7d, being provided in the gasket for this purpose. The terminals are then slidably placed through their respective openings 54, 55 in the terminal connector 24. The electrical spades 44 and as are fastened respectively as by welding to the ends of the terminal Wires 33 and 4@. Any suitable jig may be used to position properly the spades on the terminal wires during the Welding process.

Then, the assembly including the terminal block 234, the electrical spades d4, '42), the sealing member 43 and the combined coil and terminal units are positioned adjacent the unforrned straight hollow sheath The coil and terminal units are threaded through the hollow sheath until the cylindrical end portion itl of the sheath nests snugly Within the socket W of the terminal block 24 and presses against the sealing member 43 to form a positive seal against spillage.

After the assembly, the unformed sheath lb is held in a vertical position-the terminal connector end lower: most-and filled with a dielectric material, such as magnesium oxide 51. At the same time the dielectric material is compacted as by vibration and the top end closed such as at 72.

e As a last step, the filled and compacted heating unit assembly is formed into a spiral configuration, such as seen in FIGURE 1. The completed heating unit to may then be fastened to the range top as by the pivot connector bracket 22 so that the terminal block 24 is in position for receiving the male terminal block 26. For further details pertaining to the connector block 26, reierence may be had to the aforementioned Brerner latent 2,835,780.

It should now be seen that an improved top surface cooking or heating unit has been provided wherein assembly operations thereof are greatly simplified and components eliminated to provide a more efiicient manufacturing process and a less expensive product. No auxiliary fastening means are required to retain the terminal block to the tubular sheath-the electrical spades serving this purpose by their connection to the terminal Wires.

While the embodiments of the present invention as herein disclosed, constitute preferred forms, it is to be understood that other forms might be adopted.

What is claimed is as follows:

In combination, an electrical heating unit having a tubular sheath enclosing a pair of electrical heating elements and in permanently fixed relationship thereto, said tubular sheath having a closed end portion and an open end portion, said heating elements having their ends adjacent to said closed end portion of the sheath electrically connected together, a pair of electrical conductors connected respectively to said heating elements adjacent the open end portion of the sheath and extending from said open end portion of said tubular sheath, a rigid alignment member coextensive with the internal dimension of said open end portion and having a pair of holes for receiving and aligning respectively said pair of conductors 4 in said open end portion, said alignment member being positioned entirely within the confines of the tubular sheath and terminating flush with the end of the tubular sheath, a resilient sealing member coextensive with the external dimension of said open end portion and having hole means for receiving the extending portions of said electrical conductors, said sealing member being in face to face contact with said alignment member and the end of the tubular sheath, a first insulator having means defining a first pocket configured like the external dimension of said open end portion for receiving said open end portion and said sealing member and a pair of openended port means in said first insulator each smaller than said open end portion for receiving respectively the extending portions of said electrical conductors, one end or each of said port means opening into said first pocket, each of said port means having an enlarged substantially rectangular portion at one end thereof opposite from said one end and adjacent respectively to the ends of said electrical conductors, a pair or" generally flat connector tabs each having one portion configured to fit in relative non-rotatable relationship respectively to each of said enlarged rectangular portions and attached respectively to each of said electrical conductors in said enlarged-- rectangular portions to lock said tubular sheath, said sealing member, said electrical conductors and said first insulator into a unitary sandwiched assembly, said first insulator having means defining a second pocket adjacent said rectangular portions receiving another portion of each of said connector tabs therein, said other portions of said connector tabs being offset from the center of second pocket, and a second insulator having a pair of electrical contacts onset from the center thereof, "said second insulator slidably fitting into said second pocket of said first insulator with said electrical contacts respectivcly engaging said connector tabs, the oiisct of said electricalcontacts and the oifset of said connector tabs coinciding Whenever said electrical contacts and said connector tabs are properly engaged.

allots retirees Cited by the Examiner UNITED STATES PATENTS 26l7,009 11/52 Hasley 33824 l X 2,624,829 1/53 Dzaack 338-240 X 2,643,317 6/53 Tuttle 2l9-456 2,835,780 5/58 Bremer 21945l 2,840,676 6/58 King 338322 X 2,373,342 2/59 Drugrnand 29155.64 2,942,222 6/60 Nelson 338-243 2,958,121 11/60 TOSCl'lBI 29-45564 2,959,756 11/60 LfillllOX 338243 3,040,284 6/62 Connell 338-273 X 3,102,248 8/63 Temple 338274 FOREIGN PATENTS 224,047 9/59 Australia.

RICHARD M. WOOD, Primary Examiner. MAX LEVY, ANTHONY BARTIS, Examiners, 

